Thirty-four professors from the Kennedy School of Government (KSG), including Dean Joseph S. Nye, appealed to the Chinese government last week to release Yang Jianli, a KSG graduate who has been detained in China for five months.

“We ask your government, as a humanitarian gesture, to do everything in its power to facilitate Dr. Yang’s immediate release so he can return home to his family in the U.S.,” they wrote in a letter sent Sept. 16 to the Chinese ambassador to America.

Yang, who was banned from China following his involvement in the 1989 pro-democracy protests in Tiananmen Square, was detained in Kunming on April 26 for using false identification.

“His activities have violated the criminal laws of China,” said a staff member of the Chinese Foreign Ministry Spokesman’s Office who refused to provide his name. “The Beijing Public Security Organ has...according to law informed his family members.”

But his family has not received written notification of his arrest or been allowed to meet with him, according to Yang’s wife, Harvard Medical School researcher Christina X. Fu. As a result, she said, the family has been unable to obtain legal counsel for him.

“Still no word from China after 150 days, making me very worried and distressed,” Fu wrote in an e-mail. “But I remain hopeful, especially after the Harvard faculty’s letter.”

The KSG letter was organized by Ramsey Professor of Political Economy Richard J. Zeckhauser ’62 to put pressure on China before Chinese President Jiang Zemin’s upcoming visit to the U.S., which is scheduled for late October.

“We think that as a humanitarian gesture, China might contemplate releasing [Yang] in conjunction with the upcoming visit of Jiang Zemin,” Zeckhauser said.

On Sept. 19, 27 members of Congress wrote to Jiang to demand the release of Yang, who is a permanent U.S. resident. All the members of the Massachusetts delegation signed the letter.

“He is a very capable scholar and a good citizen whose only interest is the welfare of China,” Zeckhauser said of Yang, who received a Ph.D. in political economy and government from Harvard.

He also heads the Boston-based think tank Foundation for China in the 21st Century, which advocates for democracy and constitutional rule of law in China.

In the letter, the KSG professors cited the long-standing ties between Harvard and China.

“We want to make sure Dr. Yang’s detention does not interfere with our strong partnership that we hope will continue to flourish in the years to come,” they wrote in the letter.

Zeckhauser said University President Lawrence H. Summers is “very well aware of this case.”

“We’re privately engaged on this issue in a number of ways,” said Vice President for Government, Community and Public Affairs Alan J. Stone.

“Sometimes things are best done quietly rather than noisily,” Zeckhauser said. “This might be one of those cases.”

But Zeckhauser said he wants the KSG letter to make clear to China that the Harvard community is following Yang’s case closely.

“I hope the Chinese get the impression that we can move to the noisy strategy,” he said.

—Staff writer Amit R. Paley can be reached at paley@fas.harvard.edu.